Misting

• Propagation. This normally related to keeping humidity levels up and depending on the crop, keep foliage moist so the ‘cutting or Tissue Culture’ can be kept turgid while the root development occurs. Misting is normally used in conjunction with bottom heat.

Grower Technology design propagation areas that incorporate overhead misting, bottom heat from heat pads, heating cable or hot water piping in conjunction with climate control for the propagation room/area.

• Cooling of Greenhouse. Fine droplets are used to populate as much of the greenhouse volume as possible. The hot conditions evaporate the droplets creating a cooling effect by evaporative cooling. By careful control of burst time and interval then largely the coir only is cooled and minimal moisture sits on the foliage. When moisture on the foliage is desired (e.g. cuttings, propagation) the burst time is longer.

This evaporative cooling does not work in high humidity tropical climates.

Normally Netafim ‘Coolnet’ misters are utilised in cooling designs but high pressure fogging can also be used.

• Centrifugal Misting Fans. Another cooling option is centrifugal Misting Fans. Misting for cooling is best controlled by an Autofog controller or a Multigrow that will work in sync with integrated climate controls (e.g. with vents, shade screens, circulation fans etc.

• Humidification of Greenhouse. Goes hand in hand with cooling as above, and ideal targets for humidity and Temperature are aimed for. When it’s too hot and dry plants natural mechanism is to ‘shut down’ thus inhibiting growth. By lifting the humidity even 10% and lowering the temperature 3 or 4 degrees then plant growth will be healthier and stronger. This results in better growth, better yields, less disease and more profitability.

• Pad & Fan. In dry hot regions then ‘Pad & Fan’ cooling In dry hot regions then ‘Pad & Fan cooling is the best method of Greenhouse cooling in conjunction with shading. This is best controlled by the ‘Multigrow’.

When set points are breached banks of extractor fans pull air across the greenhouse. The entry point is pads where water is run into the pads. This runs down and through a multifaceted membrane, and as louvers open to the outside the air is sucked through the membrane pads cooling and humidifying the dry air creating a cool environment.